Apparatus for applying moisture resistant material to bags



Junev 1942- B. A. HANNEWALD ETAL 2,236,801

APPARATUS FOR APPLYING MOISTURE RESISTANT MATERIAL T0 BAGS Filed June 6, 1940 4 Sheets-Sheet l A 1N VENTORS- firm/wins.

June 16, 1942. B. A. HANNEWALD ET AL 2,236,801

APPARATUS FOR APPLYING MOLS'IUHE RESISTANT MATERIAL To BAGS Filed :Iune e, 1940 4 Sheets-Sheet 2 Filed June 6, 1940 4 Sheets-Sheet 3 i al B. A. HANNEWALD ET AL N l l I I l I I H -Ek 9.5.3 dufi w 3 June 16, 1942.

APPARATUS FOR APPLYiNG MOISTURE RESISTANT MATERIAL T0 BAGS June B. A. HANNEWALD ET AL 2,286,301

APPARATUS FOR APPLYING MOISTURE RESISTANT MATERIAL TO BAGS Filed June 6, 1940 4 Sheets-Sheet 4 required for spot pasting.

Patented June 16, 1942 APPARATUS FOR. APPLYING MOISTURE R SISTANT MATERIAL TO'BAGS Burton A. Hannewald, Indianapolis, Ind., and Anson M. Keller, Ferguson, Mo., asslgnors to Bemis Bro. Bag 00., Indianapolis,

ration of Missouri 1116., a corpo- Application June 6, 1940, Serial No. 339,102

8 Claims.

This invention relates to an apparatus for ap-. plying a coating of moisture resistant material over a predetermined and limited area of a bag or similar container for hygroscoplc'materials, such as sugar or the like.

In thepackaging of hygroscopic materials, of which sugar is perhaps the best example, a package, such as a paper bag, will permit moisture from the sealing paste to pass therethrough and be absorbed by the material, resulting in its caking or hardening adjacent the top of the package. This is highly objectionable, and it has heretofore been proposed that the material be protected by a coating of moisture resistant material applied over a surface extending through the area afiectedby the pasting and sealingoperation.

It is the object of this invention to provide an apparatus for applying such coating of moisture resistant material to a predetermined limited area in the production of such packages, and particularly paper bags in the line of their production. The invention'is particularly ap plicable to apparatus for rapidly producing said bags on continuous production machines in respect to the inner liners used in multi-ply paper bags In the production of such packages as paper Iii) end open for filling the finished bag with the material to be packaged. Thereafter, the open end is sealed by applying paste. It is, therefore, important in moisture proofing the bag for the purpose above mentioned, that the moisture resistant material be applied thereto over a predetermined and limited area only so as not to affect the application of paste to those portions It is also desirable that the moisture proofing be limited to the prescribedarea so as not to affect the initial folding of the top in, sealing. Furthermore, it is desirable, as a matter of economy, that the area over which the moisture resistant material is applied be limitedto accomplish the desired results while effecting a saving in the amount of such material used. Thus, this invention is directed toward a method and apparatus which will spot 'moisture proof the container, limiting the application to a predetermined area for accomplishing the desired purpose while avoiding interference with pasting and folding, and effect the desired saving in the moisture resistant material used. I

One feature of the invention resides in ap-' paratus for maintaining the moisture resistant material, such as wax, asphaltum, resins or the like, in a molten state to efiect'its ready ap-' plication.

This is accomplished by providing suitable thermostatically controlled heating elements applied to the containers for melting the material and maintaining the molten state thereof; and also to the applicator for preventing it from cooling during the application.

Another feature of the invention resides in apparatus for applying the"'moisture resistant material to a predetermined and limited area,

so arranged that such area may be varied in extent, depending upon the'size of the bag, and synchronizing its application to the various bag lengths and to the speed of travel .of the paper through a continuous production machine. This is accomplished through the medium of interchangeable applicators'of varying size and the adjustable positioning of the .feeding cylinder.

Another feature of the invention resides in apparatus for controlling the film or amount of such material applied to the bag to prevent damaging results from excessive application, particularly at the end of the stroke of the applicator. This is accomplished by providing a doctor blade which is adjustable in respect to the feeding cylinder for controlling the amount of material delivered to the applicator, and a secand doctor blade having timed cooperative movement' with the applicator for removing excess material from the trailing portion thereof as it approaches its applicating stroke.

Other features of the invention will be' more fully set forth and described in the accompanying specification and drawings.

The full nature of the invention will be understood from the accompanying drawings and the following description and claims:

Fig. 1 is illustrative of a continuous web of paper or the like indicating the prescribed areas receiving the moisture resistant material ,and the ply and seam paste. Fig. 2 is a perspective view of a paper bag showing the location of the moistration of the method and apparatus for applying the moisture resistant'material as applied to a bag making machine. Fig. 5 is a front elevation of the spot applying apparatus. Fig. 6

is an end elevation thereof. Fig. '7 is a central Fig. 8 is a central vertical section taken on the line 8-8 of Fig. 5.- I

For illustrative purposes the apparatus is herein shown and described as applied to a paper bag primarily designed to receive hydroscopic materials, such as sugar and the like, having an affinity for moisture, and wherein the bag is provided with an inner liner and known as a multiwall bag." Further, the method and apparatus as herein disclosed is primarily adapted to apply a coating of moisture resistant material to a predetermined and limited area of the liner while passing as a continuous web of paper from the feed roll and paste applying apparatus to that part of the continuous [bag making machine which joins it with the printed and decorated cover, folds and seals the sides and bottom thereof.

In the drawings there is shown a web of liner paper It) adapted to be folded longitudinally along the dotted lines H and receive a strip of adhesive material or paste indicated at |2 along one side thereof for sealing its edges and thereby form a tubular structure as it passes through a continuous bag forming machine in. conjunction with the outer decorated cover. Said web is also spotted with paste as indicated at l3, and elsewhere as indicated at I3a, and is cut to proper lengths, as indicated by the dotted lines I4.

.It is the purpose of this invention to apply a limited amount of moisture resistant material over a predetermined prescribed area on one side of the liner, as indicated at IS. The area I5 is preferably located at about a quarter of an inch from the top edge of the bag, which is indicated at l4, and between the spots of paste at |3a which secure the liner to the cover. Similarly, when the top of the bag is ultimately sealed by the application of paste thereto as at l3b, after being filled, said moisture resistant area will lie immediately thereunder for protecting the contents from moisture given off by the paste which would otherwise seep through the material to the contents, as best illustrated in Figs. 2 and 3.

The moisture resistant material is most effectively applied in a liquid condition, and may comprise paraflin wax, hot asphalt or the like. Wherein a molten material is employed it is essential that the containers therefor, feeding and applicating members be maintained within a prescribed range of temperature. This is accomplished by providing them with suitable thermostatically controlled electric heating elements.

'conduit 24 to an applying pan 25, there being provided in the conduit 24 a drainage fitting 26 controlled by a cock 21. To prevent the molten wax passing through the conduit 24 from cooling and blocking its flow, an elongated heating element 28 is mounted to extend therethrough. Thus, in the travel of the molten wax from the sump of the container 20 to the applying pan 25, it is'continuously maintained in its molten and fluid state. Again, in the applying pan, and

for continuingthe waxin its molten state, there is a heating element 29 which is governed by a thermostat 30 having an adjustment 3|.

Mounted for rotation within the applying pan and extending partially into the molten wax con tained therein, there is provided a wax feeding cylinder 36; said cylinder being driven in the direction of the arrow. Associated therewith there is an adjustable doctor blade 31 extending longitudinally of the cylinder and adjacent the periphery thereof, said blade being adjustable to control the amount of wax picked up by the cylinder in passing through the wax bath.

The moisture resistant spotting apparatus may be positioned in the usual bag making machine between the stock roll A, guide roller B and paste applying apparatus C on the left-hand side, as shown herein, and that portion of the machine on the right-hand side which feeds the cover material to the paper liner, and which applies paste at D, folds it as indicated at E, seals the paper in tubular form, cuts it to length, and seals the bottom (not shown).

For the purpose of locating the wax application with respect to the paste application and cutting to length, a shaft 4| is driven in timed relation with the machine above referred to, and particularly the rate of movement therethrough of the paper I0. Said shaft carries thereon an applicatorshoe 42 supported by the arms 43. Said shoe is moved in a circular path by the shaft 4|, in the direction of the arrow, and the length of the arms 43 is such as to cause the effective or applicating surface of the shoe to engage with the film of wax carried by the cylinder 36 and transfer it to the paper II), pressing the paper against the pressure roller 40. Due

to the synchronized drive of the shaft 4| with w the travel of the paper ill, the hoe "will move with the paper, contacting it throughout the effective surface thereof. Thus, the spotting of the wax is governed in area by the effective surface of the shoe and as to location on the paper by the timed relation thereof and length of the arms 43.

The radius of the circular path of travel of the applicator shoe controls the spacing of the spots in accordance with the length of the bag being produced. Wherein the length of the bag is shortened, the arms 43 and, therefore, the

radius of the applicator would be reduced, and wherein the length of the bag is increased, the

- the relative location of the 'spot on a bag of predetermined length, and the area of the spot is governed by the length of the arms 43 and the effective area of the shoe 42.

When the wax is applied to the paper by the shoe 42, a surplus of wax would normally be squeezed from the trailing portion or tail end thereof. This would be detrimental to the proper application of the wax, and to eliminate it there may be thereby controlled.

aeeasoi approaches the paper. Through suitable cam mechanism hereinafter described, said blade is at the extreme end thereof and carrying an elec-v tric control panel 52 therebelow. The operating frame 53 is supported upon the table and carries at the top thereof a horizontally extending rock shaft 54 carrying the pressure roller 40. Said roller is pivotally mounted between a pair of spaced arms 55 secured to said rock shaft, their upward movement being yieldingly resisted by a spring 55 connected to an arm 51 secured to one end thereof, and their downward position limited by suitable adjustable stops.

The applicator shoe i2 is mounted on the shaft M to rotate therewith. Said shaft is driven by a sprocket wheel 58 which in turn is driven by a chain 59 from the driving sprocket 50 of the bag making machine or the adjacent paste applying apparatus generally indicated at C. As shown in Fig. 4, the shaft 4! is driven to make one revolution for each tube from which the bag is formed. Said shaft 6! is carried by the bearings 63 and is provided with a driving gear 65 which drives a driven gear 65 keyed to a shaft 66 carrying the feeding cylinder 36. As shown in Fig. 8, gear 55 is driven through the idler gears 61 carried upon a quadrant 68 which is adjustable about the shaft 4| andsecured inv adjusted position by a lock nut Sloperating in the arcuate slot 50.

to Figs. and 6,

portion thereof passes thereby, but is moved into close proximity of the tail end of the sh'oe for wax just prior to its passing wiping off the excess movement.

In the use of wax or asphaitum as a moisture resistant material, it is desirable to maintain .it 1 in a molten state during its feeding and appli- 1 cation. To this end, not only is the container 29, conduit 2d and applying pan provided with suitable heating elements, but the shoe t2, is

electrically heated by securing an element 81 to the inner surface thereof and connecting it by a circuit passing along the shaft ea energized by a suitable brush contact'indicated at 81. It is also desirable to heat the intermittent doctor blade 44 so as to prevent an accumulation of wax thereon. For that purpose the blade car rier 83 is provided with a heating element 88 which is connected in the circuit.

The level of the molten material in the apply-,

for applying paste along the seam,'folding and cutting the tube to length.-

The shaft 68 with its driven gear 65 and cylinder 36 is removably supported in the bearing cradles H mounted upon a carrier bracket '82 which is slidable upon the ways 13. The adjusting screws I4 which are operated by the adjusting handles 15, are connected to the carrier '52 for adjusting the position of the feeding cylinder within the wax bath to accommodate it to applicator shoes of varying radial length. In this manner, different applicator shoes may be mounted on the shaft 4| 'for spotting the web to provide tubes or bags of different length. The feeding cylinder may be adjusted thereto by the handles 15 and the adjustment of the idler gears 61 by the quadrant 88.

The carrier bracket 12 carries integrally therewith the forwardly extending arms 16 upon which a doctor blade 31 is slidably mounted andadjustable in respect to the surface of the feeding cylinder 36 by the adjusting screws Tl. 'By adjustment of'the blade 31 the amount of wax carried by the "cylinder to the applicator shoe For intermittently operating the doctor blade 44, the shaft 4| is provided with a cam 18 (Figs. 7 and 8). Pivotally mounted upon a rocker shaft 19 there is an arm 80 carrying a cam follower 8!, said camfollower being maintained in engagement with the cam through the tension of a spring 82. Rigidly secured to the rocker shaft 79, as by welding or the like, there is a blade support 83 carrying the doctor blade 44. Said doctor blade is adjustable with respect to the blade carrier by means of the slots 85 and lock screws 8'6 operating therein. The shape of the cam I8 I The apparatus is adjustable to receive various weight or length of bag, the distance of travel by the shoe 42 through one cycle being equivalent to the tube length. To adjust the apparatus to a shorter or longer length bag, the length of the arms 43 carrying the shoe is changed, preferably by substituting a proper size shoe on the shaft H. The area of the moisture proofing spotgmay likewise'be controlled by varying or interchanging the shoes 42. In changing the shoe to vary the length of the arms 43, it may be noted that the curvature of the applicator surface is .correspondingly varied to have the same radius of curvature as the path through which it'travels. The relative position of the feeding cylinder 36 is accordingly changed by the adjusting handles 15 which are'operated toslide its supporting carriage to a position wherein. it is substantially tangential with the path of movement of the shoe. Such adjustment carries the doctor blade 37 therewith, which inturn may be adjusted relative to the feeding cylinder for-varying the amount of moisture proofing material ,to be applied. The location of the spot-is then determined by the relative positioning ofythe' shoe. on the shaft 4!. v

Having effected adjustments of the machine to obtain the desired area of the spot, its locais such that the doctor blade is moved upwardly tion and the amount of material to be applied, the electric heating elements may be energized through manipulation of theswitches on the panel board 52. After the material has become molten, the machine mayv then be started for continuous operation. v

While reference isherein made to, a' paper bag, it is to be understood that said terms are employed in their broadest sense as pertaining to any similar container or packaging formed of equivalent materials, and spotted .by a liquid substance having moisture resistant characteristics in the nature of wax or asph Fun ther, the wax may be applied while in a molten state as herein described, or if desired, in the form of a cold liquid mulch. Wherein the applicator has'been described,,for example, in the form of va shoe carried by arms, it may similarly be 'in the form of an intaglio cylinder or the like.

feeding cylinder rotatable in said container and tlidriven by said driving means in feeding lation with the surface of said. shoe, a cam i ii'ven'in timed relation with the said applicator shoe, a rock shaft actuated'by said cam, a doctor blade, and means adapted to adjustably support said blade on said rock shaft adjacent the path of movement of said shoe as it approaches the paper web, said cam.acting to rock saidblade for moving it away from the path of the shoe while the fore part thereof passes and moving it to adjacent the trailing end of said shoe for removing excess material therefrom.

2. An apparatus for spotting a continuously moving web of bag making paper with a moisture resistant material including a container for the material, an electric element in said container for heating the material to a molten state, a

pan for containing molten material at a predetermined level, an electric element in said pan for maintaining the material in its molten state, a conduit connecting said container with said pan, whereby molten material may be fed from the former to the latter, an electric element in said conduit for maintaining the material in a molten state while passing therethrough, thermostatic control means for regulating the heating of said material and maintaining a predetermined level of molten material in said pan, and means radius determined by the length of the bag, and

means for removing excess material from the cylinder and the trailing portion of the shoe as it approaches the web.

4. An apparatus for spotting a continuously moving web of bag making paper with a moisture resistant material including a container for the material, an electric element associated with said container for heating the material to a molten state, a pan for receiving said molten material at a predetermined level relative to said container, a conduit connecting said container with said pan, whereby said molten material maybe fed from the former to the latter, thermostatic control means for regulating said electric element adapted to maintain a predetermined level of molten material in said pan, and means for transferring'a film of said material fromsaid pan to said moving web of paper in timed relation therewith for applying a spot of material thereto of predetermined location and prescribed area.

5. An apparatus for spotting'a continuous web of bag making paper with a moisture resistant material including a pan for containing said material, a carriage slidably mounted with respect to said pan, a feeding cylinder rotatably mounted on said carriage, an applicator having an effective surface of predetermined area, the radius of movement of said applicator being determined by the length of the bag produced from said web,

means for adjusting the position of said carriage for moving said cylinder into feedin relation with said applicator surface, a shaft upon which said applicator is mounted, means for driving said shaft and cylinder in timed relation including a pinion, and means foradjusting said pinion to compensate for variations in the radius of movement of the applicator surface and the corresponding adjusted position of said cylinder.

6. An apparatus for spotting a continuously moving web of bag making paper with a moisture resistant material including a pan for containfor transferring a film of molten material from i said pan to said moving web of paper in timed relation therewith for applying a spot of said material thereto of predetermined location and prescribed area.

3. An apparatus for spotting a continuously moving web of bag making paperwith a moisture resistant material including a container for the material, an electric element in said container for heating the material to a molten state, a pan for containing molten wax at a predetermined level, an electric element in said pan for maintaining the material in its molten state, a conduit connecting said container with said pan, whereby molten material may be fed from the former to the latter, an electric element in said conduit for maintaining the material in a molten state while passing therethrough, thermostatic.

control means for regulating the heating of said material and maintaining a predetermined level of molten material in said pan, a feeding cylinder rotatable in said pan partially immersed in said molten material, a rotating shoemovable to receive a film of material from said cylinder for transfer to the moving web of papenmeans for driving said web and shoe in timed relation, the path of movement of said shoe having a ing a bath of said material in a liquid state, a

bath, an applicator rotatable with said cylinder and having an effective surface of predetermined area movable in feeding relation thereto, the path of movement of said applicator surface extending into the path of the paper and being of a radius determined by the length of the bag produced from said web, means for adjusting said cylinder for feeding relation with applicators of varying radius of movement, a pressure roll mounted above thepath of movement of the web against which said web is pressed upon engagement thereto by the applicator, an arm for rotatably supporting said pressure ,roll, a rock shaft connected with said arm, a lever mounted on said rock shaft, and yielding means connected with said leverfor maintaining said roll and web in position to be yieldingly engaged by said aD- I I area movable in feeding relation thereto, the

path of movement of said applicator surface extending into the path of the paper and being of a radius determined by the length of the bag for accommodation to varying radii of the path of movement of said applicator, a doctorbla-de' slidably mounted on said carriage, and means for adjusting the relative position of said doctor blade 'andcylinder for controlling the film of material carried thereby to said applicator.

8. An apparatus for spotting a continuously movingweb of bag making paper of a moisture resistant material including a pan for containing a bath of said material in a liquid state, a feeding cylinder mounted for rotation in said bath, an applicator rotatable with said cylinder and having an efiectivesurface of predetermined area movable in feeding relation thereto, the path-0f movementof said applicator surface ex,-

tending into the path of the paper and being of a radius determined by the length of the bag produced from saidweb, means for adjusting the position of said cylinder with respect to said applicator surface for accommodation to varying. radii of the path oimovement of said'applicator, a doctor'blade extending adjacent the path of movement of said applicator for removing excess material-therefrom, a blade carrier for adjustably supporting said blade for accommodation to varying radii of the path of movement of 

